How is lateral or roll stability typically achieved in an airplane?

Lateral or roll stability in an airplane is typically achieved through the design feature known as dihedral. Dihedral refers to the upward angle of the wings relative to the horizontal plane. This configuration provides stability because when the aircraft begins to roll to one side, the wing on that side experiences a decrease in lift due to a change in angle of attack. Conversely, the opposite wing, which is at a higher angle, generates more lift. This differential lifting effect naturally causes the airplane to roll back toward level flight, thus enhancing stability.

The other options do not contribute to lateral stability in the same way. Increasing engine power during a turn does not inherently affect roll stability, as it can lead to increased yawing and potential loss of control if not managed properly. Reducing weight on the wings does not inherently enhance stability; instead, the distribution of weight and its impact on the center of gravity play more critical roles. Finally, while a stabilator can improve pitch control and responsiveness, it primarily pertains to pitch stability and does not have a significant effect on lateral stability.